Silicone Compound and a Use Thereof

ABSTRACT

The purpose is to provide a silicone compound which is well compatible with polymerizable silicone monomers and other polymerizable monomers to provide a polymer having high oxygen permeability, excellent hydrophilicity and anti-staining property, excellent dimension stability, and enough durability of mechanical strength not to deteriorate in a phosphate buffer solution. The other purpose is to provide a silicone compound having a high blocked terminal ratio and a high ratio of one specific structure and a method for preparing the silicone compound. The invention provides a compound represented by the following formula (1). 
     
       
         
         
             
             
         
       
     
     Further, the invention provides a method for preparing the compound, use of the compound as an ophthalmic monomer, a polymer having repeating units derived from the aforesaid compound and an ophthalmic device composed of the polymer.

CROSS REFERENCE

This application claims the benefits of Japanese Patent Application Nos.2014-121257 filed on Jun. 12, 2014, and 2015-112952 filed on Jun. 3,2015, the contents of which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a compound which is useful as startingmaterials for preparing ophthalmic devices such as contact lenses,intraocular lenses and artificial corneas, hereinafter also referred toas ophthalmic monomer, and a method for the preparation thereof.Specifically, the present invention relates to a compound which iscopolymerizable with the other polymerizable monomer such as a(meth)acryl monomer to provide a polymer having high transparency andoxygen permeability, excellent hydrophilicity, anti-staining propertyand durability of mechanical strength and being suitable for ophthalmicuses, and a method for preparing the silicone compound. In particular,the present invention relates to a compound which functions as acrosslinking component for a polymerizable silicone monomer.

The following silicone compounds are known as an ophthalmic monomer.

The afore-mentioned TRIS, 3-[tris(trimethylsiloxy) silyl]propylmethacrylate, has poor compatibility with hydrophilic monomers such as2-hydroxyethyl methacrylate (HEMA). Therefore, when TRIS iscopolymerized with a hydrophilic monomer, there is such a disadvantagethat a transparent polymer is not obtained. In contrast, SiGMA describedabove has good compatibility with hydrophilic monomers such as HEMA. Thecopolymers obtained from SiGMA have relatively high oxygen permeabilityand high hydrophilicity. Recently, higher oxygen permeability isrequired for an ophthalmic polymer so as to be used continuously on eyesfor a longer term. Polymers obtained from SIGMA do not have sufficientoxygen permeability.

In order to solve this problem, Japanese Patent Application Laid-OpenNo. 2007-186709, Patent Literature 1, describes a compound representedby the following formula (a).

In the afore-mentioned SiGMA, the weight ratio of the Si-containingmoiety, i.e. bis(trimethylsiloxy)methylsilyl, to the whole molecule is52%. In contrast, in the aforesaid formula (a), the weight ratio of theSi-containing moiety, i.e. tris(trimethylsiloxy) silyl, to the wholemolecule is 60%. The compound represented by the formula (a) thus hasthe higher weight ratio of the Si-containing moiety and, therefore,gives higher oxygen permeability to ophthalmic devices.

However, there is a problem such that when the weight ratio of theSi-containing moiety is increased in order to improve oxygenpermeability, the mole weight of the polymerizable group became largeand, therefore, strength of the copolymer deteriorated. Japanese PatentApplication Laid-Open No. 2007-1918, Patent Literature 2, describes thatthe compound represented by the aforesaid formula (a) is prepared by areaction of a corresponding epoxy precursor and methacrylic acid. Thereis such a problem such that many side reactions occur and the physicalproperties of the resulting copolymers vary.

Japanese Patent No. 4882136, Paten Literature 3, describes a compoundrepresented by the following formula (e) and an ophthalmic lens preparedfrom a polymer having repeating units derived from the compound.

However, the polymer obtained by polymerization using the aforesaidcompound as a monomer component has poor mechanical strength, and areactivity of the polymerization of the compound is poor. Further, aanti-staining property of the polymer obtained is insufficient. PatentLiterature 3, claim 3, also describes a monomer having a urethane bond.However, this monomer has such a siloxane structure astris(trimethylsiloxy)silyl, bis(trimethylsiloxy)methylsilyl andpentamethyldisiloxane, and does not has a chain siloxane structure. Apolymer obtained from a monomer of this structure may have lower oxygenpermeability or a bad shape recovery property.

It is known that a silicone having a tetrameric or more structure isthought to be preferable in term of oxygen permeability and, inparticular, a silicone having a tetrameric or pentameric structure isthought to be more preferable in order to balance between oxygenpermeability and strength of the copolymer. Therefore, development of amethod for preparing a silicone monomer having a tetrameric or morestructure with a high purity is desired.

Japanese Patent Application Laid-Open No. Sho 59-78236, PatentLiterature 4, describes a method for the preparation of a siliconecompound represented by a following formula (b), comprising steps ofanion-polymerizing a cyclic siloxane in the presence of a lithiumtrialkylsilanolate as an initiator and, then, reacting the reactionproduct with a chlorosilane having a (meth) acryl group, such as3-(2-methacryloyloxy ethoxy) propyl dimethyl chlorosilane.

However, when the silicone compound obtained in the afore-mentionedmethod is mixed with a hydrophilic monomer, such as 2-hydroxyethylmethacrylate, turbidity occurs sometimes. Further, a ratio of terminalsof the silicone chain blocked with the chlorosilane is not high.

Japanese Patent Application Laid-Open No. 2001-55446, Patent Literature5, describes a method for preparing a silicone compound represented bythe following formula (c) by esterifying (meth)acrylic acid ortransesterifying (meth)acrylate with an organopolysiloxane having ahydroxyl group at the one terminal,

wherein r is an integer of 3 or larger.However, the esterification ratio is insufficient, the blocked terminalratio is low, and the compound has broad distribution of apolymerization degree of the silicone moiety.

Japanese Patent No. 4646152, Patent Literature 6, describes a method forpreparing a silicone monomer represented by the following formula (d) byesterifying an organopolysiloxane having a hydroxyl group at the oneterminal and a (meth) acrylic acid halide:

wherein m is one value out of the integers of from 3 to 10, n is onevalue out of 1 and 2, R¹ is only one out of alkyl groups having 1 to 4carbon atoms, and R² is only one out of a hydrogen atom and a methylgroup,

and more than 95 weight % of the compound is one kind of compound havingthe specific one structure, i.e., each one value of m, n, R¹ and R².

A monomeric compound having a fluorinated hydrocarbon group wasdeveloped in order to increase oxygen permeability of its polymer or addanti-staining property to its polymer. For instance, Japanese NationalPhase Publication No. 2003-516562 describes a method for copolymerizinga hydrophilic monomer, a monomer having tris(siloxysilyl) group and amonomer having a fluorinated hydrocarbon group.

Japanese Patent Application Laid-Open No. 2008-274278 and JapaneseNational Phase Publication No. 2013-507652 describe afluorine-containing silicone monomer having a siloxane chain to which afluorinated hydrocarbon group bonds as a side chain and a polymerizablegroup, represented by the following formula.

wherein X is a polymerizable group, R₁ is, independently of each other,an alkyl group having 1 to 6 carbon atoms or —R₄—CF₃, wherein R₄ is,independently of each other, an alkenyl group having 1 to 6 carbonatoms, R₂ is, independently of each other, an alkenyl group having 1 to6 carbon atoms or a fluorine-containing alkenyl group having 1 to 6carbon atoms, R₃ is a group selected from the group consisting of amonovalent linear or branched alkyl group, a siloxane chain having 1 to30 Si—O units, a phenyl group, a benzyl group, a linear or branchedhetero atom-containing group, or a combination of these, m is 1 to 6, nis 0 to 14, p is 1 to 14, a total of n and p is 15 or less, Y is adivalent connecting group, a is 0 or 1, q is 1 to 3, r is 3-q.

Japanese Patent Application Laid-Open No. 2013-112776, Patent Literature10, describes a (meth)acryl group containing organopolysiloxanerepresented by the following formula (I).

wherein R is an unsubstituted or substituted monovalent hydrocarbon oralkoxy group which has 1 to 20 carbon atoms and no (meth)acryl group. Qis, independently of each other, represented by the following “A” or“X”, provided that at least one Q is “A”. A is a group represented by—R¹—CONH—C(R²) [CH₂—O—CO—CH═CH₂]₂ or —R¹—CONH—C(R²)[CH₂—O—CO—C(CH₃)=CH₂]₂, wherein R¹ is a divalent organic group, R² is aan unsubstituted or substituted monovalent hydrocarbon group, which has1 to 20 carbon atoms or an alkoxy group and no (meth) acryl group. X isselected from the groups defined for R and a monovalent organic groupwhich has an active hydrogen atom and no (meth) acryl group. “a” is aninteger of from 0 to 1,000 and “b” is and integer of from 0 to 100.

The silicone compound is prepared by reacting an organopolysiloxanemodified with a monovalent organic group having an active hydrogen atomand an isocyanate compound having a hydrocarbon group with two (meth)acryl groups.

PRIOR LITERATURES Patent Literature 1: Japanese Patent ApplicationLaid-Open No. 2007-186709 Patent Literature 2: Japanese PatentApplication Laid-Open No. 2007-1918 Patent Literature 3: Japanese PatentNo. 4882136

Patent Literature 4: Japanese Patent Application Laid-Open No. Sho59-78236

Patent Literature 5: Japanese Patent Application Laid-Open No.2001-55446 Patent Literature 6: Japanese Patent No. 4646152 PatentLiterature 7: Japanese National Phase Publication No. 2003-516562 PatentLiterature 8: Japanese Patent Application Laid-Open No. 2008-274278Patent Literature 9: Japanese National Phase Publication No. 2013-507652Patent Literature 10: Japanese Patent Application Laid-Open No.2013-112776 SUMMARY OF THE INVENTION

An additional polymerizable monomer is often used as a crosslinkingagent to increase a crosslinking degree of a polymer having repeatingunits derived from an ophthalmic silicone monomer so as to increasedurability of mechanical strength. For instance, polyfunctional (meth)acrylates such as ethylene glycol dimethacrylate are used as thecrosslinking agent. However, the polyfunctional (meth) acrylate does nothave a silicone chain and, therefore, oxygen permeability of a polymerobtained is lower sometimes or a crosslinking degree of a polymer issometimes too high, so that shrinkage may cause in curing and dimensionstability may be bad.

A polymer is needed that its mechanical strength does not deteriorate ina phosphate buffer solution so as to be well used as an ophthalmicdevice. Further, increased oxide permeability and anti-staining propertyare required for the polymer at the same time. Therefore, a siliconecompound is desired which well works as a crosslinking agent for apolymerizable silicone monomer and provides a polymer having higheroxide permeability, excellent durability of mechanical strength in aphosphate buffer solution, anti-staining property and dimensionstability.

The silicone compounds described in Patent Literatures 1 to 6 have onlyone (meth) acryl group and does not work as a crosslinking agent.Further, a polymer obtained from the compound has poor durability ofmechanical strength, so that the mechanical strength may deteriorate ina phosphate buffer solution. Patent Literatures 7 to 9 describes amonomer compound having a fluorinated hydrocarbon group. However, thesesilicone compounds also have only one (meth) acryl group and does notwork as a crosslinking agent. Further, these silicone compounds are lesscompatible with the other polymerizable monomers.

In the methods described in Patent Literatures 8 and 9, control of thenumber of siloxane repeating units having a fluorinated hydrocarbongroup is difficult and, therefore, a product obtained is a mixture ofcompounds having various amounts of fluorine atoms. Further, the amountof fluorine atoms is too large, the compatibility between the compoundand the other monomers is worse, a polymer obtained becomes cloudy andmicrophase separation occurs. Further, mechanical strength of a polymerobtained from the monomer may deteriorate in a phosphate buffersolution.

The silicone compound described in Patent Literature 10 has plural(meth)acryl groups in the molecular, so that has high cross-linkingefficiency. However, the silicone compound has poor compatibility withother polymerizable monomers. Further, the silicone compound has manysiloxane units. The organopolysiloxane has many siloxane units and largemolecular weight distribution and, therefore, the purity of theorganopolysiloxane is low and a polymer obtained is a mixture ofpolymers. Further, a polymer obtained from the monomer has poorertransparency. The monomer having a silicone chain which has a higherpolymerization degree has sometimes poor compatibility with otherpolymerizable monomers to cause turbidity.

Therefore, one of the purposes of the present invention is to provide asilicone compound which functions well as a crosslinking agent for apolymerizable monomer. Specifically, the purpose is to provide asilicone compound which is well compatible with polymerizable siliconemonomers and other polymerizable monomers to provide a polymer havinghigh oxygen permeability, excellent hydrophilicity, anti-stainingproperty and dimension stability, and enough durability of mechanicalstrength not to deteriorate in a phosphate buffer solution. The otherpurpose is to provide a silicone compound having a high blocked terminalratio and a high ratio of one specific structure and a method forpreparing the silicone compound.

The present inventors have made research to solve the afore-mentionedproblems and found that a compound represented by the following formula(1) is well compatible with other polymerizable monomers, in particular,polymerizable silicone monomers, functions well as a crosslinkingcomponent, and provides a colorless and transparent polymer which hasexcellent hydrophilicity, anti-staining property and durability ofmechanical strength.

Thus, the present invention provides a compound represented by thefollowing formula (1):

wherein m is an integer of from 2 to 10, n is an integer of from 1 to 3,R¹ is, independently of each other, an alkyl group having 1 to 6 carbonatoms, R² is, independently of each other, an alkylene group having 1 to6 carbon atoms or a fluoroalkylene group having 1 to 6 carbon atoms, R³is an alkyl group having 1 to 4 carbon atoms, R⁶ is a substituted orunsubstituted alkyl group which has no (meth) acryl group and has 1 to20 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, and R⁴,R⁵, R⁷ and R⁸ are, independently of each other, a hydrogen atom or amethyl group.

Further, the present invention provides a method for preparing thecompound, use of the compound as an ophthalmic monomer, a polymer havingrepeating units derived from the aforesaid compound and an ophthalmicdevice composed of the polymer.

Effects of the Invention

The present silicone compound is well compatible with other (meth) acrylmonomers and functions well as a crosslinking component. Further, thepresent compound has the specific amount of fluorine atoms to therebyprovide a polymer having excellent anti-staining property. The presentcompound has the specific amount of silicon atoms to thereby have ahigher oxygen permeability. The present compound provides a polymerhaving excellent hydrophilicity and durability of mechanical strength.

The mechanical strength of the polymer does not deteriorate in aphosphate buffer solution. The present silicone compound has one kind ofspecific structure at a high ratio, to thereby provide a colorless andtransparent polymer by copolymerization with the polymerizable monomer.The present method comprises a reaction of a silicone compound having ahydroxyl group and a (meth) acryl group-containing isocyanate compound.The present method provides a compound having one kind of specificstructure at a high ratio. Accordingly, the present compound and thepresent method are useful for preparing ophthalmic devices.

BRIEF EXPLANATION OF THE DRAWING

FIG. 1 is a chart of ¹H-NMR spectra of the silicone compound prepared inExample 1.

DETAILED DESCRIPTION OF THE INVENTION

The present silicone compound is represented by the aforesaid formula(1), and has a silicone chain structure having a fluorinated hydrocarbonside group, a urethane structure in a spacer structure bonding thesilicone structure and the (meth)acryl structure, and an alkyleneoxidestructure between the urethane structure and the silicone structure. Onaccount of the aforesaid specific structures, the present compound iswell compatible with other polymerizable monomers and provides acolorless and transparent polymer having a higher oxygen permeabilityand increased hydrophilicity, anti-staining property and durability ofmechanical strength. Further, the present silicone compound has two(meth) acryl groups at the one terminal. Therefore, the compoundfunctions well as a crosslinking component to provide a polymer havingexcellent durability of mechanical strength and dimension stability.

In the aforesaid formula (1), m is an integer of from 2 to 10,preferably 3 to 7, more preferably 3. If m is smaller than the lowerlimit, the oxygen permeability of the polymer is worse. If m is largerthan the upper limit, the hydrophilicity of the polymer is worse. When mis within the aforesaid limits, the compound has a linear siloxanestructure having the desired amount of silicon atoms, so that a polymerobtained has good oxygen permeability and shape recovery property.

In the aforesaid formula (1), R⁵ is, independently of each other, ahydrogen atom or a methyl group. n is an integer of from 1 to 3. Thepresent compound has an alkyleneoxide structure in the part bonding theurethane bond and the siloxane structure to thereby has the goodhydrophilicity. If n is zero, the hydrophilicity is worse. If n islarger than 3, the compound does not have one kind of a specificstructure at a high ratio and a polymer thereof has poor durability andmechanical strength. Preferably, n is 1 or 2 and the silicone compoundpreferably has an ethylene oxide structure, an ethylene oxide-ethyleneoxide structure, an ethylene oxide-propylene oxide structure or apropylene oxide-ethylene oxide structure.

According to the aforesaid structure, the compound has good balance ofhydrophilicity. Particularly, preferred is the compound having anethylene oxide structure whose n is 1 and R⁵ is a hydrogen atom. If thecompound has too many propylene oxide structures, the hydrophobicity ofthe polymer obtained is too high and the hydrophilicity is poorer.

In the aforesaid formula (1), R¹ is, independently of each other, analkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethylgroup, a propyl group, a butyl group, a pentyl group and a hexyl group.Among these, a methyl group is preferable.

In the aforesaid formula (1), R² is, independently of each other, analkylene group having 1 to 6 carbon atoms or a fluoroalkylene grouphaving 1 to 6 carbon atoms. Examples of the alkylene group include amethylene group, an ethylene group, a propylene group, a butylene group,a pentylene group and a hexylene group. Examples of the fluoroalkylenegroup include 2,2-difluoroethylene, 3,3-difluoropropylene,3,3,4,4-tetrafluorobutylene, 3,3,4,4,5,5-hexafluoropentylene and3,3,4,4,5,5,6,6-octafluorohexylene. Among these, an ethylene group ispreferable.

In the aforesaid formula (1), R³ is an alkyl group having 1 to 4 carbonatoms, preferably a butyl group, and R⁴, R⁵, R⁷ and R⁸ are,independently of each other, a hydrogen atom or a methyl group. R⁶ is asubstituted or unsubstituted monovalent hydrocarbon group which has no(meth)acryl group and has 1 to 20, preferably 1 to 10 carbon atoms, oran alkoxy group having 1 to 10, preferably 1 to 6 carbon atoms. Examplesof the monovalent hydrocarbon group include alkyl groups such as amethyl group, an ethyl group, a propyl group, a butyl group, a pentylgroup, a hexyl group, a heptyl group, an octyl group, a nonyl group anda decyl group; cycloalkyl groups such as a cyclopentyl group and acyclohexyl group; aryl groups such as a phenyl group and a tolyl group;alkenyl groups such as a vinyl group and an allyl group; and thosehydrocarbon groups wherein a part or all of the hydrogen atoms bonded tothe carbon atoms of these groups are substituted with a halogen atomsuch as a chlorine atom and a fluorine atom. Among these, a methylgroup, an ethyl group, a propyl group and a butyl group are preferableand a methyl group is particularly preferable.

The present method of the invention provides one kind of compound whichis represented by the formula (1) and has one specific structure havingeach specific one value of m and n at a high ratio, as will describedbelow. A high ratio means that an amount of the aforesaid one kind ofcompound having an each specific one value of m and n, based on a totalamounts of the compound represented by the formula (1), is more than 95mass %, preferably 97 mass % or more, further preferably 99 mass % ormore. One kind of compound having one specific structure is particularlya compound having an each specific one value of m, n, R¹, R², R³, R⁴,R⁶, R⁷ and R⁸ and a specific one kind of alkyleneoxide structure. In thepresent invention, the ratio is determined in gas chromatography,hereinafter referred to as “GC”. The details of GC will be describedbelow. When the compound is mixed with a non-silicone monomer such as2-hydroxyethyl methacrylate, any turbidity does not occur and atransparent polymer is obtained, because the starting compound has ahigh ratio of one specific structure. If the ratio is less than 95 mass%, for instance, other compounds having different values of m arecontained in an amount of more than 5 mass %, a mixture of the presentsilicone compound and a non-silicone monomer is turbid and does notprovide a colorless and transparent polymer.

When m is 3, n is 1, R¹ is a methyl group, R² is an ethylene group, R³is a butyl group, R⁴ and R⁵ are each a hydrogen atom, R⁶ is a methylgroup and R⁷ and R⁸ are each a hydrogen atom in the formula (1), themolecular weight is 1081 and a content of siloxanes is approximately 43mass %, based on the total mass of the compound other than thefluoromethyl group and a content of fluorine atoms is approximately 21mass %, based on the total mass of the compound. That is, the compoundcomprises a large amount of Si atoms, whereby a polymer obtainedtherefrom has high oxygen permeability. Further, the compound has adesired amount of a fluorine atom and, therefore, anti-staining propertyof a polymer is improved.

The present invention further provides methods for preparing theafore-mentioned compound represented by the formula (1).

One of the present methods comprises a step of reacting a siliconecompound represented by the following formula (2):

wherein m, n, R¹, R², R³, R⁴ and R⁵ are as defined above; with a(meth)acryl group-containing isocyanate compound represented by thefollowing formula (3):

wherein R⁶, R⁷ and R⁸ are as defined above.The reaction is preferably carried out in such a manner that the (meth)acryl group-containing isocyanate compound represented by the formula(3) is slowly added to a solution of the polyorganosiloxane representedby the formula (2) in toluene or hexane to be allowed to react at atemperature of from 0 to 50 degrees C. under cooling, for instance, in awater bath.

The amount of the (meth) acryl group-containing isocyanate compound (3)is 1 to 3 moles, preferably 1.05 to 2 moles, per mole of thepolyorganosiloxane represented by the formula (2). If the amount issmaller than the lower limit, the polyorganosiloxane (2) would remainunreacted in the reaction product and a high ratio of one specificstructure of the formula (1) is not attained. If the amount is largerthan the upper limit, this is economically disadvantageous.

The afore-mentioned reactions may be carried in the presence of acatalyst. Any catalyst generally used for isocyanate reactions may beused. Preferred are tin compound catalysts and amine catalysts. As thetin compound catalysts, a tin (II) salt of carboxylic acid anddioctyltin oxide are preferred for its catalyst activity. As the aminecatalysts, tertiary amines such as triethylamine, tributylamine andN-ethyldiisopropylamine are preferred. The amount of the catalyst may be0.001 to 0.1 part by mass, preferably 0.005 to 0.05 part by mass, per100 parts by mass of the component (2). If the amount is larger than theupper limit, the catalyst effect may saturate and this is noteconomically. If the amount is smaller than the lower limit, an enoughcatalyst effect is not attained, so that the reacting rate is slow andproductivity is worse.

In the afore-mentioned reactions, a polymerization inhibitor may beadded, if needed. Any conventional polymerization inhibitor for a (meth)acryl compound may be used, such as, for instance, a phenol typepolymerization inhibitor such as hydroquinone, hydroquinone monomethylether, 2-tert-butyl hydroquinone, 4-methoxy phenol and2,6-di-tert-butyl-4-methylphenol (BHT). These may be used singly or twoor more of them may be used in combination. The amount is preferably 5to 500 ppm, further preferably 10 to 100 ppm, based on an amount ofcompound to be obtained, but is not limited to these.

It is preferred that the unreacted silicone compound (2) is monitored inGC. After disappearance of its peak is confirmed, an alcohol, such asmethanol or ethanol, is poured into the reaction mixture to inactivatethe isocyanate group of the unreacted (meth) acryl group-containingisocyanate compound. Subsequently, an organic solvent and water areadded to the mixture and stirred and, then, left standing to allowseparation into an organic phase and an aqueous phase. The organic phaseis washed several times with water and, then, a silicone compound (1)which has one specific structure is obtained at a high ratio bystripping off the solvent present in the organic phase because almost noside reaction occurs.

The silicone compound represented by the aforesaid formula (2) isprepared by an addition reaction of a polyorganohydrogen siloxanerepresented by the following formula (4)

wherein m, R¹, R² and R³ are as defined above; with a compoundrepresented by the following formula (5), hereinafter referred to as“allyl ether compound”:

wherein n, R⁴ and R⁵ are as defined above.

This addition reaction may be carried out in any conventional manners.For instance, the reaction is carried out in the presence of ahydrosilylation catalyst such as platinum group metal compounds. Asolvent may be used. Examples of the solvent include aliphatic oraromatic solvents such as hexane, methylcyclohexane, ethylcyclohexaneand toluene; and alcoholic solvents such as ethanol and IPA. A ratio ofthe aforesaid compounds to be used may be according to conventionalmanners. The amount of the allyl ether compound may be 1.2 moles ormore, preferably 1.5 moles or more, per mole of the polyorganohydrogensiloxane. The upper limit of the amount may be usually 5 moles or less,particularly 3 moles or less, but is not limited to them.

The allyl ether compound represented by the aforesaid formula (5) ispreferably represented by the following formulas.

It is preferred that the ally ether compound is optionally diluted witha solvent to which, then, a hydrosilylation catalyst of platinum familyis added. Any conventional hydrosilylation catalysts of platinum familymay be used and not limited to any particular one. Subsequently, thepolyorganohydrogen siloxane is added dropwise to the mixture to react atroom temperature or a higher temperature. After the completion of theaddition, the reaction mixture is held under heating, untildisappearance of the peak of the raw material,polyorganohydrogensiloxane, is confirmed, for instance, in GC. After theend point of the reaction is confirmed in GC, the unreactedpolyorganohydrogen siloxane does not remain in a product, so that asilicone compound obtained has one specific structure at a higher ratio.The aforesaid addition reaction may be conducted in one step.

After the completion of the addition reaction, an excessive allyl ethercompound is removed from the reaction liquid. For instance, the reactionliquid is subjected to stripping under a reduced pressure, or washedwith ion exchanged water or an aqueous sodium sulfate solution toextract the allyl ether compound into an aqueous phase. Here, a properamount of solvent, such as toluene and hexane, may preferably be used toattain clear phase separation. In particular, the solvent is strippedoff from the organic phase under a reduced pressure, whereby thesilicone compound represented by the aforesaid formula (2) and having ahigh ratio of one specific structure such as more than 95 mass %, evenapproximately 97 mass % or more, further approximately 99 mass % ormore, is obtained. The silicone compound may be distilled twice or moreto further increase the ratio. A high ratio means that an amount of theaforesaid one kind of compound having each specific one value of m andn, based on a total amounts of the compound represented by the formula(2), is more than 95 mass %, preferably 97 mass % or more, furtherpreferably 99 mass % or more. The one specific structure means one kindof compound having each one value of m and n, particularly, one kind ofcompound having each one value of m, n, R¹, R², R³ and R⁴ and one kindof alkylene oxide structure.

The polyorganohydrogen siloxane represented by the aforesaid formula (4)may be prepared in known manners. For instance, the compound (4) whereinm is 3, R¹ is a methyl group, R² is an ethylene group and R³ is a butylgroup may be prepared in the following manner. First, BuMe(CF₃CH₂CH₂)SiOLi is synthesized using BuLi.

1,3,5-Tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclo trisiloxane issubjected to a ring-opening reaction using the BuMe (CF₃CH₂CH₂)SiOLi asan initiator and, then, the reaction is terminated withdimethylchlorosilane. Thus, a mixture of compounds having m of 2 to 5 isobtained. The mixture is distillated to collect a fraction at 146degrees C. and 84 Pa to obtain a compound whose m is 3, at a ratio of 98mass % or higher in the fraction obtained. Alternatively, thedistillation may be carried out after the mixture is addition reactedwith the allyl ether compound represented by the formula (5). However,the product of the addition reaction has a higher boiling point.Therefore, the former manner is preferred. Then, a silicone compound (2)having one specific structure is obtained at a higher ratio.

The silicone compound (2) may be prepared also by the steps ofsubjecting the allyl ether to a silylation to provide a silyl ester witha silylating agent such as hexamethyldisilazane, addition reacting thecompound obtained in the aforesaid manners and, then, hydrolyzing thesilyl ester.

The silicone compound of the present invention is well compatible withother compounds having a group polymerizable with the siliconecompounds, such as compounds having a (meth) acryl group, hereinafterreferred to as “polymerizable monomer”. Therefore, the silicone compoundcopolymerizes with the polymerizable monomer to provide a colorless andtransparent polymer. In particular, the silicone compound is wellcompatible with a fluorinated substituent group-containing (meth) acrylmonomer, so that hydrophilicity and anti-staining property of thepolymer obtained are increased.

Examples of the polymerizable monomer include acryl monomers such as(meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate,(poly)ethylene glycol dimethacrylate, polyalkylene glycol mono (meth)acrylate, polyalkylene glycol monoalkyl ether (meth) acrylate,trifluoroethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and2,3-dihydroxypropyl (meth) acrylate; acrylic acid derivatives such as N,N-dimethyl acrylamide, N, N-diethyl acrylamide, N-acryloyl morpholine,and N-methyl (meth) acrylamide; other ethylenically unsaturatedaliphatic or aromatic compound such as crotonic acid, cinnamic acid, andvinyl benzoic acid; and silicone compounds having polymerizable groupssuch as a (meth)acryl group. These may be used singly or two or more ofthem may be used in combination.

Additionally, the present silicone compound has two (meth) acryl groups,so that it functions well as a crosslinking component. Therefore, thesilicone compound is useful as a crosslinking agent for a polymerizablemonomer and provides a colorless and transparent polymer having gooddurability of mechanical strength. In particular, the present compoundis well compatible with a silicone monomer having a polymerizable groupsuch as a (meth)acryl group. Any conventional polymerizable monomersknown as ophthalmic monomers may be used. In particular, preferred aresilicone monomers having a (meth) acryl group at the one terminal and asiloxane structure at the other terminal. For instance, siliconemonomers described in Patent Literatures 1 to 6 may be used.

When the present silicone compound is used as a crosslinking agent, theamount of the silicone compound may preferably be 0.1 to 50 parts bymass, further preferably 0.5 to 20 parts by mass, relative to 100 partsby mass of the total amount of the other polymerizable monomers, inparticular, the other polymerizable silicone monomer. Because thepresent silicone compound has one specific structure at a high ratioitself, a polymer obtained has high transparency.

Further, one or more other compounds which function as a crosslinkingcomponent may be polymerized with the present silicone compound and theaforesaid polymerizable monomer. The compound may be bifunctional orpolyfunctional (meth) acrylates. Examples of the bifunctional acrylatesinclude 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate,neopentylglycol diacrylate, polyethylene glycol diacrylate,neopentylglycol hydroxypivalate diacrylate, dicyclopentanyl diacrylate,caprolactone-modified dicyclopentenyl diacrylate, ethyleneoxide-modified phosphate diacrylate, allylated cyclohexyl diacrylate,and isocyanurate diacrylate. Examples of the polyfunctional acrylatesinclude trimethylol propane triacrylate, dipentaerythritol triacrylate,propionic acid-modified dipentaerythritol triacrylate, pentaerythritoltriacrylate, propylene oxide-modified trimethylolpropane triacrylate,tris(2-acryloxyethyl) isocyanulate, dipentaerythritol pentaacrylate,propionic acid-modified dipentaerythritol pentaacrylate,dipentaerythritol hexaacrylate, and caprolactone-modifieddipentaerythritol hexaacrylate. Examples of the bifunctionalmethacrylates include ethylene glycol dimethacrylate, triethylene glycoldimethacrylate, 1,4-butanediol dimethacrylate, neopentylglycoldimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanedioldimethacrylate, 1,10-decanediol dimethacrylate, glycerin dimethacrylate,and dimethyloltricyclodecane dimethacrylate. Examples of thepolyfunctional methacrylates include trimethylol propane trimethacrylateand ethoxylated trimethylol propane trimethacrylate. The amount of thecompound may be preferably 0.1 to 50 parts by mass, further preferably0.5 to 20 parts by mass, relative to 100 parts by mass of the totalamount of the other polymerizable monomers.

The copolymerization of the present compound and the other polymerizablemonomer mentioned just above may be carried out in conventional knownmanners. For instance, known polymerization initiator such as thermalpolymerization initiators or photo polymerization initiators may beused.

Examples of the polymerization initiator include2-hydroxy-2-methyl-1-phenyl-propane-1-one, azobis isobutyronitrile,azobis dimethylvaleronitrile, benzoyl peroxide, tert-butylhydroperoxide, and cumene hydroperoxide. The polymerization initiatormay be used singly or two or more of them may be used in combination.The amount of the polymerization initiator is 0.001 to 2 parts by mass,preferably 0.01 to 1 part by mass, relative to 100 parts by mass of atotal amount of the polymerizable components.

A polymer having a unit derived from the compound in the presentinvention has high oxygen permeability and excellent hydrophilicity,anti-staining property and durability of mechanical strength in aphosphate buffer solution. Therefore, the present compounds are suitableas materials for preparing ophthalmic devices such as contact lenses,intraocular lenses and artificial corneas. A method for preparation ofthe ophthalmic device with the present polymer may be any conventionalones. For instance, a machining method and a molding method may be usedfor forming lenses such as contact lenses and intraocular lenses.

EXAMPLES

The present invention will be explained below in further detail withreference to a series of the Examples and the Comparative Examples,though the present invention is in no way limited by these Examples.

In the following descriptions, a viscosity was determined by aCannon-Fenske viscosimeter and a specific gravity was as determined by ahydrometer. A refraction index was as determined by a digitalrefractometer RX-5000, ex Atago Co., Ltd. ¹H-NMR analysis was conductedby JNM-ECP500, ex JEOL Ltd. with deuterochloroform as a measuringsolvent.

A ratio of a compound was determined by gas chromatography, i.e. GC.Conditions in GC were as follows.

[GC Conditions]

Gas chromatograph: ex Agilent Technologies, Inc.Detector: FID, temperature of 300 degrees C.Capillary Column: HP-5MS (0.25 mm×30 m×0.25 micrometer), ex J & WTemperature rise program: 50 degrees C. for 5 minutes, 10 degreesC./minute and, then, maintained at 250 degrees C.Temperature at an inlet: 250 degrees C.Carrier gas: Helium with a flow rate of 1.0 ml/minuteSplit ratio: 50:1Injection volume: 1 microliter

Synthesis Example 1

In a three-liter flask equipped with a stirring device, a dimrothcondenser, a thermometer and a dropping funnel, put were 112.4 g (0.24mol) of 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane and 60 g of toluene, and cooled to an internal temperatureof 0 degrees C. Then, 450 ml (0.72 mol) of a 1.6 M solution ofn-butyllithium was added dropwise in the flask over two hours at theinternal temperature of 0 to 15 degrees C. The reaction mixture was heldat 15 degrees C. for one hour, to which a mixture of 337.4 g (0.72 mol)of 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclo trisiloxaneand 270 g of tetrahydrofuran was then added dropwise over two hours atthe internal temperature of 0 to 5 degrees C. The reaction mixture wasaged at the internal temperature of 0 to 5 degrees C. for two hours and,then further at the internal temperature of 20 to 25 degrees C. for onehour. 7.3 g (0.72 mol) of triethylamine was added to the reactionmixture and, then, 88.6 g (0.94 mol) of dimethyldichlorosilane was addeddropwise in the flask over two hours at the internal temperature of 20to 25 degrees C. The reaction mixture was aged at the internaltemperature of 20 to 25 degrees C. for one hour. 1000 Grams of waterwere added to the reaction mixture, stirred for 5 minutes and, then,left standing to cause phase separation. The aqueous phase wasdiscarded. The solvent in the organic phase was distilled off under areduced pressure to obtain 526 g of a mixture comprising 57.1% of thedesired compound. The mixture was distillated to collect a fraction at146 degrees C. and 84 Pa to obtain 255 g of a product with a yield of47.8%(0.34 mol). ¹H-NMR analysis showed that the product was a compoundrepresented by the following formula (6). The ratio of the compoundrepresented by the following formula (6) in the obtained product was98.4 mass %, as determined in GC, the viscosity was 11 mm²/s at 25degrees C., the specific gravity was 1.144 at 25 degrees C. and therefraction index was 1.3810.

Example 1

In a one-liter flask equipped with a stirring device, a dimrothcondenser, a thermometer and a dropping funnel, put were 38.25 g (0.375mol) of ethylene glycol monoallyl ether represented by the followingformula (7) and 100 g of toluene, and heated to 70 degrees C. 0.38 Gramof a solution of a catalyst, complex of alkali-neutralizedchloroplatinic acid with vinyl siloxane, in toluene, containing 0.5% ofplatinum, was added in the flask. Then, 185 g (0.25 mol) of the compoundrepresented by the aforesaid formula (6) was added dropwise in the flaskwith the dropping funnel over one hour. The reaction mixture was held at100 degrees C. for one hour and, then, analyzed in GC. The peak of thecompound represented by the aforesaid formula (6) disappeared, whichmeans that the reaction completed. 100 Grams of ion exchanged water wereadded to the reaction mixture with stirring to wash it and, then, leftstanding to cause phase separation. The aqueous phase containing theexcessive ethylene glycol monoallyl ether was removed. The organic phasewas similarly washed twice with each 100 g of ion exchanged water and,then, the toluene in the organic phase was stripped off under a reducedpressure to obtain 193.7 g (0.23 mol) of a colorless and transparentliquid, silicone compound represented by the following formula (8). Theyield was 92%. The ratio of the silicone compound represented by thefollowing formula (8) in the obtained product was 98.1 mass %, asdetermined in GC.

In a one-liter flask equipped with a stirring device, a dimrothcondenser, a thermometer and a dropping funnel, put were 210.5 g (0.25mol) of the silicone compound represented by the formula (8), 0.02 g(0.01 mass %) of dioctyl tin oxide, 0.01 g of Ionol, i.e.2,6-di-tert-butyl-4-methylphenol, ex Japan Chemtech Co. Ltd., and 0.01 gof 4-methoxyphenol to prepare a mixture. 62.1 Grams (0.26 mol) of amethacryl group-containing isocyanate compound represented by thefollowing formula (9) was added dropwise to the mixture over one hour.The internal temperature rose from 20 degrees C. up to 25 degrees C. Themixture was held at 40 degrees C., while monitoring the peak of thesilicone compound represented by the formula (8) in GC. Four hourslater, the intensity of the peak of the silicone compound fell downbelow the detection limit by GC and, then, 4.0 g (0.125 mol) of methanolwas added to the reaction mixture. Further, 180 g of hexane and 180 g ofion exchanged water were added to the reaction mixture to wash it. Thereaction mixture was left standing to cause phase separation. Theaqueous phase was removed and, subsequently, the organic phase waswashed twice with ion exchanged water. The solvent, hexane, was strippedoff from the organic phase under a reduced pressure to obtain 213.5 g ofa colorless and transparent liquid product. ¹H-NMR analysis showed thatthe obtained compound in the product was a silicone compound representedby the following formula (10), hereinafter referred to as siliconecompound 1. The yield was 79% and the aforesaid amount (213.5 g) was 0.2mol. The ratio of the silicone compound represented by the followingformula (10) in the product was 97.3 mass %, as determined in GC, theviscosity was 258.8 mm²/s at 25 degrees C., the specific gravity was1.171 at 25 degrees C. and the refraction index was 1.4199.

Comparative Synthesis Example 2

The procedures of Example 9 described in Japanese Patent ApplicationLaid-Open No. 2008-274278, Patent Literature 8, were repeated tosynthesize a polysiloxane represented by the following formula (11). Theobtained product was a mixture of a compound whose m was 0, a compoundwhose m was 3, a compound whose m was 6, and a compound whose m was 9,hereinafter referred to as silicone compound 2.

Comparative Synthesis Example 3

The procedures of Example 1 described in Japanese Patent No. 4646152,Patent Literature 6, were repeated to synthesize a compound representedby the following formula (12), hereinafter referred to as siliconecompound 3.

The obtained compound was a colorless and transparent liquid. The ratioof the silicone compound represented by the aforesaid formula (12) inthe obtained product was 98.3 mass %, as determined in GC.

Comparative Synthesis Example 4

The procedures of Example 1 described in Japanese Patent ApplicationLaid-Open No. 2013-112776, Patent Literature 10, were repeated tosynthesize a compound represented by the following formula (13),hereinafter referred to as silicone compound 4. The silicone compoundobtained was a mixture of compounds having various values of n with anaverage of 60 in the following formula. The viscosity was 87 mm²/s at 25degrees C. and the refraction index was 1.4082.

Comparative Synthesis Example 5

In a one-liter flask equipped with a stirring device, a dimrothcondenser, a thermometer and a dropping funnel, put were 43.5 g (0.75mol) of allyl alcohol and 100 g of toluene, and heated to 70 degrees C.0.38 Gram of a solution of a catalyst, complex of alkali-neutralizedchloroplatinic acid with vinyl siloxane, in toluene, containing 0.5% ofplatinum, was added in the flask. Then, 206 g (0.5 mol) of1-butyl-9-hydro-1,1,3,3,5,5,7,7,9,9-decamethylpentasiloxane was addeddropwise in the flask with the dropping funnel over one hour. Theinternal temperature rose up to 85 degrees C. The reaction mixture washeld at 100 degrees C. for one hour and, then, analyzed in GC. The peakof the raw material, monobutyl decamethyl hydropentasiloxane,disappeared, which means that the reaction completed. 200 Grams of ionexchanged water was added to the reaction mixture with stirring to washit and, then, left standing to cause phase separation. The aqueous phasecontaining the excessive ethylene glycol monoallyl ether was removed.The organic phase was washed similarly twice with each 200 g of ionexchanged water and, then, the toluene in the organic phase was strippedoff under a reduced pressure to obtain 223 g of a colorless andtransparent liquid, silicone compound represented by the followingformula (14). The yield was 95%. The ratio of the silicone compoundrepresented by the following formula (14) in the obtained compound was99.6 mass %, as determined in GC.

The procedures of Example 1 were repeated, except that 117.5 g (0.25mol) of the silicone compound represented by the formula (14) was usedin place of 128.5 g (0.25 mol) of the silicone compound represented bythe formula (8). 145.3 Grams of a colorless and transparent liquidproduct was obtained. ¹H-NMR (300 MHz) analysis showed that the obtainedcompound in the product was a silicone compound represented by thefollowing formula (15), hereinafter referred to as silicone compound 5.The yield was 82% and the aforesaid amount (145.3 g) was 0.2 mol. Theratio of the silicone compound represented by the following formula (15)in the product was 97.8 mass %, as determined in GC, the viscosity was75.6 mm²/s at 25 degrees C., the specific gravity was 1.023 at 25degrees C. and the refraction index was 1.4451.

Comparative Synthesis Example 6

The procedures of Comparative Synthesis Example 5 were repeated, exceptthat 142.5 g (0.75 mol) of the tri(ethylene glycol)monoallyl ether wasused in place of 43.5 g (0.75 mol) of allyl alcohol. 273.9 Grams of acolorless and transparent liquid product was obtained. ¹H-NMR analysisshowed that the obtained compound in the product was a silicone compoundrepresented by the following formula (16). The yield was 91%. The ratioof the silicone compound represented by the following formula (16) inthe product was 99.1 mass %, as determined in GC.

The procedures of Example 1 were repeated, except that 150.5 g (0.25mol) of the silicone compound represented by the formula (16) was usedin place of 128.5 g (0.25 mol) of the silicone compound represented bythe formula (8). 168.2 Grams of a colorless and transparent liquidproduct was obtained. ¹H-NMR (300 MHz) analysis showed that the obtainedcompound in the product was a silicone compound represented by thefollowing formula (17), hereinafter referred to as silicone compound 6.The yield was 80% and the aforesaid amount (168.2 g) was 0.2 mol. Theratio of the silicone compound represented by the following formula (17)in the product was 97.8 mass %, as determined in GC, the viscosity was96.2 mm²/s at 25 degrees C., the specific gravity was 1.010 at 25degrees C. and the refraction index was 1.437.

Examples 2 to 3 and Comparative Examples 1 to 7

Monomer mixtures 1 to 9 were prepared in the following manners, usingthe silicone compounds 1 prepared in Example 1 and silicone compounds 2to 6 prepared in Comparative Synthesis Examples 2 to 6. In the followingExample 3, trifluoroethyl methacrylate were not used. In the followingComparative Example 6, triethylene glycol dimethacrylate was used inplace of the silicone compounds as a crosslinking agent. In thefollowing Comparative Example 7, no crosslinking agent was used.

Preparation of a Monomer Mixture Example 2

60 Parts by mass of the polymerizable silicone monomer which isrepresented by the following formula (18), TRIS, ex Gelest, Inc., 30parts by mass of N, N-dimethyl acryl amide, 1 part by mass of siliconecompound 1 prepared in Example 1, 10 parts by mass of trifluoroethylmethacrylate, and 0.5 part by mass of DAROCUR 1173, i.e.,2-hydroxy-2-methyl-1-phenyl-1-propanone, as a photopolymerizationinitiator, ex Ciba Specialty Chemicals Inc., were mixed and stirred toobtain monomer mixture 1.

Example 3

60 Parts by mass of the polymerizable silicone monomer which isrepresented by the aforesaid formula (18), TRIS, ex Gelest, Inc., 30parts by mass of N, N-dimethyl acryl amide, 1 part by mass of siliconecompound 1 prepared in Example 1, and 0.5 part by mass of DAROCUR 1173,ex Ciba Specialty Chemicals Inc., were mixed and stirred to obtainmonomer mixture 2.

Comparative Examples 1 to 5

In Comparative Example 1, the same components and the same manners as inExample 2 were used, except that silicone compound 2 was used instead ofsilicone compound 1 to obtain monomer mixture 3.

In Comparative Example 2, the same components and the same manners as inExample 2 were used, except that silicone compound 3 was used instead ofsilicone compound 1 to obtain monomer mixture 4.

In Comparative Example 3, the same components and the same manners as inExample 2 were used, except that silicone compound 4 was used instead ofsilicone compound 1 to obtain monomer mixture 5.

In Comparative Example 4, the same components and the same manners as inExample 2 were used, except that silicone compound 5 was used instead ofsilicone compound 1 to obtain monomer mixture 6.

In Comparative Example 5, the same components and the same manners as inExample 2 were used, except that silicone compound 6 was used instead ofsilicone compound 1 to obtain monomer mixture 7.

Comparative Example 6

In Comparative Example 6, the same components and the same manners as inExample 2 were used, except that 1 part by mass of triethylene glycoldimethacrylate was used instead of silicone compound 1 to obtain monomermixture 8.

Comparative Example 7

60 Parts by mass of the polymerizable silicone monomer which isrepresented by the aforesaid formula (18), TRIS, ex Gelest, Inc., 30parts by mass of N, N-dimethyl acryl amide, 10 parts by mass oftrifluoroethyl methacrylate, and 0.5 part by mass of DAROCUR 1173, exCiba Specialty Chemicals Inc., were mixed and stirred to obtain monomermixture 9.

[Evaluations]

Monomer mixtures 1 to 9 obtained were evaluated in the followingmanners. The results are as shown in Table 1.

(1) Compatibility with Other Polymerizable Monomers

The appearances of the monomer mixtures obtained were observed visually.A mixture comprising a silicone compound having good compatibility withthe other (meth)acryl compounds was colorless and transparent. Incontrast, a mixture comprising a silicone compound having badcompatibility with the other (meth)acryl compounds was turbid.

(2) Appearance of a Film, Composed of the Polymer

The each mixture was deaerated in an argon atmosphere. The mixtureobtained was poured into a mold having two pieces of quartz glass plateswhich faced each other. The mixture was irradiated with light from anextra high pressure mercury lamp for one hour to obtain a film having athickness of approximately 0.3 mm. The appearance of the film wasobserved visually.

(3) Water Wettability, or Hydrophilicity, of a Film Surface, Composed ofthe Polymer

Water contact angles of the films prepared in (2) above were determinedby a liquid drop method with a contact angle meter CA-D type, ex KyowaInterface Science Co., LTD.

(4) Anti-Staining Property of a Film, Composed of the Polymer

Two films for each one mixture were prepared in the same manner as in(2) above. One of the twos was soaked in a phosphate buffer solution,PBS(−), at 37 degrees C. for 24 hours. The film after soaked and anotherfilm without being soaked were stored in a well-known artificial lipidsolution at 37 plus—minus 2 degrees C. for 8 hours. Then, the films werewashed with PBS(−) and, subsequently, soaked in a 0.1% solution of sudanblack sesame oil. When the colors were not different between the filmafter soaked and the film without being soaked, the film was evaluatedas “good”. When the color of the film after soaked was different fromthe film without being soaked, that is, the film was stained with thesudan black sesame oil, the film was evaluated as “bad”.

(5) Durability of Mechanical Strength of a Film, Composed of the Polymer

Two films for each one mixture were prepared in the same manner as in(2) above. Any water on the surface of the films was wiped off. Then,one of the twos was soaked in a phosphate buffer solution, PBS(−), at 37degrees C. for 24 hours. The film after soaked and another film withoutbeing soaked were cut into test samples having a dumbbell shape of awidth of 2.0 mm. The top and the bottom of the test sample was held by ajig and pulled at a constant speed. Tensile strength and elongation atbreak were determined with a tensile tester AGS-50NJ, ex ShimadzuCorporation. When a change of the value of the tensile strength or therupture elongation of the film after soaked, relative to the value ofthe film without being soaked was not larger than 10%, it was evaluatedas “good”. When a change of the value of the tensile strength or therupture elongation of the film after soaked, relative to the value ofthe film without being soaked was larger than 10%, it was evaluated as“bad”.

TABLE 1 Example Example Com. Ex. Com. Ex. Com. Ex. Com. Ex. Com. Ex.Com. Ex. Com. Ex. 2 3 1 2 3 4 5 6 7 Monomer mixture 1 2 3 4 5 6 7 8 9(1) Colorless Colorless Turbid Slightly Turbid Slightly SlightlySlightly Slightly Compatibility and and turbid turbid turbid turbidturbid transparent transparent (2) Colorless Colorless Cloudy SlightlyCloudy Slightly Slightly Slightly Slightly Appearance of and and cloudycloudy cloudy cloudy cloudy the film transparent transparent (3) 50 4758 60 66 56 47 62 57 Water contact angle, ° (4) Good Good Bad Bad BadBad Bad Bad Bad Anti-staining property (5) Good Good Bad Bad Bad GoodBad Bad Bad Durability of mechanical strength

The compounds used in Comparative Examples 1-3 and 5-7 were lesscompatible with the other (meth) acryl monomers and did not provide acolorless and transparent polymer. Further, the polymers obtained fromthe monomer mixtures had poor water wettability (hydrophilicity) andanti-staining property and the mechanical strength deteriorated in thephosphate buffer solution. The compound used in Comparative Example 4was less compatible with the other (meth)acryl monomers and did notprovide a colorless and transparent polymer. Further, the polymersobtained from the monomer mixtures had poor water wettability(hydrophilicity) and anti-staining property. Triethylene glycoldimethacrylate does not have any silicone chain and has poorcompatibility with a silicone monomer. Therefore, as shown in Table 1,Comparative Example 6, a transparent polymer was not provided.

In contrast, the silicone compound of the present invention is wellcompatible with the other (meth)acryl monomer and provides a colorlessand transparent polymer. Further, the silicone compound is wellcompatible with a fluorinated (meth)acryl monomer, too. Therefore, thesilicone compound provides a polymer having excellent water wettabilityand anti-staining property and mechanical strength. The mechanicalstrength does not deteriorate in the phosphate buffer solution. Further,as shown in Example 3 of Table 1, the present silicone compoundprovides, on account of its fluorinated hydrocarbon group, a polymerhaving an excellent anti-staining property without other fluorinatedmonomer.

As shown in Comparative Example 7, the polymerizable silicone monomer,TRIS, was less compatible with the other (meth)acryl monomer compoundsand did not provide a transparent mixture or polymer.

In contrast, as shown in Table 1, Examples 2 and 3, when the presentsilicone compound was mixed with the mixture of the polymerizablesilicone monomer, TRIS, and the other (meth) acryl compounds, atransparent mixture and polymer were provided. That is, the presentsilicone compound of the second aspect functioned well as acompatibilizing agent in addition to a crosslinking agent.

INDUSTRIAL APPLICABILITY

The compound of the second aspect of the present invention is wellcompatible with the other polymerizable monomers, in particular(meth)acryl silicone monomers and fluorinated substituentgroup-containing (meth)acryl silicone monomers. A polymer having a unitderived from the present compound has good oxygen permeability, hascolorlessness and transparency, and good mechanical strength, and,further has good hydrophilicity and anti-staining property. Further themechanical strength of the polymer obtained does not deteriorate in aphosphate buffer solution and the durability of mechanical strength isexcellent. Further, the present method provides a compound having onespecific structure at a high ratio. Accordingly, the present compoundand the present method are useful for preparing ophthalmic devices suchas contact lenses, intraocular lenses and artificial corneas.

1. A compound represented by the following formula (1):

wherein m is an integer of from 2 to 10, n is an integer of from 1 to 3,R¹ is, independently of each other, an alkyl group having 1 to 6 carbonatoms, R² is, independently of each other, an alkylene group having 1 to6 carbon atoms or a fluoroalkylene group having 1 to 6 carbon atoms, R³is an alkyl group having 1 to 4 carbon atoms, R⁶ is a substituted orunsubstituted monovalent hydrocarbon group which has no (meth)acrylgroup and has 1 to 20 carbon atoms, or an alkoxy group having 1 to 10carbon atoms, and R⁴, R⁵, R⁷ and R⁸ are, independently of each other, ahydrogen atom or a methyl group.
 2. The compound according to claim 1,wherein an amount of one kind of compound having each one value of m andn in the formula (1) is more than 95 mass % of a total mass of thecompound.
 3. The compound according to claim 1, wherein m in the formula(1) is
 3. 4. A polymer having repeating units derived from the compoundaccording to claim 1 and repeating units derived from at least one othercompound having a group which is polymerizable with said compound. 5.The polymer according to claim 4, wherein the other compound includes asilicone monomer.
 6. The polymer according to claim 5, an amount of thecompound according to any one of claims 1 to 3 is 0.1 to 50 parts bymass, relative to 100 parts by mass of the silicone monomer.
 7. Anophthalmic device composed of the polymer according to claim
 4. 8. Amethod for preparing a compound represented by the following formula(1):

wherein m is an integer of from 2 to 10, n is an integer of from 1 to 3,R¹ is, independently of each other, an alkyl group having 1 to 6 carbonatoms, R² is, independently of each other, an alkylene group having 1 to6 carbon atoms or a fluoroalkylene group having 1 to 6 carbon atoms, R³is an alkyl group having 1 to 4 carbon atoms, R⁶ is a substituted orunsubstituted monovalent hydrocarbon group which has no (meth)acrylgroup and has 1 to 20 carbon atoms, or an alkoxy group having 1 to 10carbon atoms, and R⁴, R⁵, R⁷ and R⁸ are, independently of each other, ahydrogen atom or a methyl group, comprising a step of reacting asilicone compound represented by the following formula (2):

wherein m, n, R¹, R², R³, R⁴ and R⁵ are as defined above; with a(meth)acryl group-containing isocyanate compound represented by thefollowing formula (3):

wherein R⁶, R⁷ and R⁸ are as defined above.
 9. The method according toclaim 8, wherein an amount of one kind of compound having each one valueof m and n in the formula (1) is more than 95 mass % of a total mass ofthe compound.
 10. The method according to claim 8, wherein m in theformula (1) is 3.